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Stray-field imaging and multinuclear magnetic resonance spectroscopy studies on the setting of a commercial glass-ionomer cement
A commercial glass-ionomer (Fuji II) was studied using different NMR techniques. 1.H and 19.F stray-field imaging (STRAFI) were used to monitor the curing kinetics of the cement and two processes were distinguished: the gelation and maturation phases. Characterization of the aluminium and silicon species present in the glass component and cement was performed by conventional 27.Al and 29.Si MAS and two-dimensional 27.Al triple quantum MAS NMR (MQMAS) techniques. Quantification of the aluminium in the glass component and in the cement indicates the leaching of about 32 % of the 4-coordinate aluminium, about 100 % of the 5-coordinate aluminium and about 41 % of the 6-coordinate aluminium, during the setting reaction. It is also shown that the 5-coordinate aluminium is only present in the surface layer created by the acid attack during the cement formation process. In the cement, silicon maintains species with four bridging oxygens after the leaching of tetrahedral (4-coordinate) aluminium. The silicon analysis correlates well with the aluminium determinations.
Stray-field imaging and multinuclear magnetic resonance spectroscopy studies on the setting of a commercial glass-ionomer cement
A commercial glass-ionomer (Fuji II) was studied using different NMR techniques. 1.H and 19.F stray-field imaging (STRAFI) were used to monitor the curing kinetics of the cement and two processes were distinguished: the gelation and maturation phases. Characterization of the aluminium and silicon species present in the glass component and cement was performed by conventional 27.Al and 29.Si MAS and two-dimensional 27.Al triple quantum MAS NMR (MQMAS) techniques. Quantification of the aluminium in the glass component and in the cement indicates the leaching of about 32 % of the 4-coordinate aluminium, about 100 % of the 5-coordinate aluminium and about 41 % of the 6-coordinate aluminium, during the setting reaction. It is also shown that the 5-coordinate aluminium is only present in the surface layer created by the acid attack during the cement formation process. In the cement, silicon maintains species with four bridging oxygens after the leaching of tetrahedral (4-coordinate) aluminium. The silicon analysis correlates well with the aluminium determinations.
Stray-field imaging and multinuclear magnetic resonance spectroscopy studies on the setting of a commercial glass-ionomer cement
Untersuchung des Aushärteverhaltens eines dentalen Glasionomerzements mit Hilfe verschiedener NMR-Techniken
Pires, R. (author) / Nunes, T.G. (author) / Abrahams, I. (author) / Hawkes, G.E. (author) / Morais, C.M. (author) / Fernandez, C. (author)
Journal of Materials Science - Materials in Medicine ; 15 ; 201-208
2004
8 Seiten, 6 Bilder, 5 Tabellen, 21 Quellen
Article (Journal)
English
Stray Field Magnetic Resonance Imaging
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